Rsync to upload certain files and ignore others

[jediknight2]

Is there a way for RSYNC when its backing up a folder say c:\output to
ignore certain file extentions as a whole...so basically ignore all other
files EXCEPT *.gpg files??  the file extensions are all random so it might
be thisone.th, thatone.pz, etc...but when I encrypt them all the files are
encrypted an have the .gpg extension so basically I have thisone.th and
thisone.th.gpg, thatone.pz and thatone.pz.gpg